1. Field of the Invention
This invention relates to novel compositions derived from the reaction of particular ketene-animals with particular olefins and the use of said compositions as catalysts in the trimerization of organic isocyanates.
2. Description of the Prior Art
There are numerous catalysts known in the art for the trimerization of isocyanates and most of them suffer from a drawback of one sort or another. For example, in the preparation of isocyanurate-modified polyisocyanates the trimerization must be interrupted by the addition of a catalyst poison as taught in U.S. Pat. No. 3,330,828. Alternatively, in the use of self-deactivating catalysts such as the ar-sulfonium arenoxide zwitterions as taught in U.S. Pat. No. 4,111,914, the catalysts are expensive and difficult to prepare. Also, the prior art catalysts often result in highly colored products which are not stable upon storage and some products even emit odors due to the catalyst.
In regard to the complete trimerization of isocyanates using prior art catalysts, one of the problems has been the achievement of good conversion to polyisocyanurate once the polymer has gelled. Concurrently, once the polymer has solidified the catalyst cannot be removed and the majority of prior art catalysts have an adverse effect on polymer properties over prolonged periods.
I have now discovered what I believe to be novel compositions which act as catalysts in trimerizing organic isocyanates. The catalysts in accordance with the present invention overcome the drawbacks of the prior art catalysts noted above and their advantageous features will be discussed in detail below.